Hello,
The LTC7000 datasheet states: "Normally the SNS pins are connected to the drain side of the external MOSFET. However, the SNS pins can be connected to the source side of the external MOSFET...". I made some assumptions after reading this and would like to get some clarification. There are no example schematics that show this alternative SNS pin connection configuration so I am a bit confused as to how this can work exactly.
Are the following configurations valid:
1. Current sense resistor between the MOSFET's source pin and the TS pin of the device. SNS+/- directly measuring across this resistor. See the quick schematic below.
2. Current resistor after TS and MOSFET source pin. SNS+/- still measuring across this resistor.
I simulated both configurations in LTSpice and the over-current/short circuit behavior appears to be identical between these two configurations and the typical "SNS pins connected to the drain pin of the MOSFET" configuration. The simulation results makes me think that this could work but I would like to get confirmation. Configuration 2 (illustrated above) would help us reuse the shunt resistor and current measurement for a different circuit so we are hopping this is a valid configuration for the SNS pins.
Thank you
Edit Notes
Change subjtect title to mention SNS pins instead of sense resistor.[edited by: jleyva at 2:33 PM (GMT -5) on 21 Nov 2025]
